[PATCH] drm/ttm: fix regression in ttm moves

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

This fixes a bug introduced in be1213a341a289afc51f89181c310e368fba0b66
drm/ttm: remove TTM_MEMTYPE_FLAG_FIXED v2

On vmwgfx this causes a Command buffer error WARN to trigger.

This is because the old code used to check if bo->ttm was true,
and the new code doesn't, fix it code to add back the check resolves
the issue.

Fixes: be1213a341a2 ("drm/ttm: remove TTM_MEMTYPE_FLAG_FIXED v2")
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 70b3bee27850..e8aa2fe8e9d1 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -251,9 +251,11 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
 		/* Zero init the new TTM structure if the old location should
 		 * have used one as well.
 		 */
-		ret = ttm_tt_create(bo, old_man->use_tt);
-		if (ret)
-			goto out_err;
+		if (!bo->ttm) {
+			ret = ttm_tt_create(bo, old_man->use_tt);
+			if (ret)
+				goto out_err;
+		}
 
 		ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
 		if (ret)
-- 
2.20.1